Messages in this thread |  | | Date | Thu, 7 Feb 2013 10:54:01 -0800 | Subject | Re: [PATCH 3/4] spi: s3c64xx: add gpio quirk for controller | From | Girish KS <> |
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On Thu, Feb 7, 2013 at 3:55 AM, Mark Brown <broonie@opensource.wolfsonmicro.com> wrote: > On Tue, Feb 05, 2013 at 03:09:43PM -0800, Girish K S wrote: >> This patch adds support for spi controllers with >> dedicated clk/miso/mosi/cs pins. It skips the gpio >> parsing and initialization for controllers that >> have dedicated pins. > >> if (sdd->tgl_spi != spi) { /* if last mssg on diff device */ >> /* Deselect the last toggled device */ >> cs = sdd->tgl_spi->controller_data; >> - gpio_set_value(cs->line, >> - spi->mode & SPI_CS_HIGH ? 0 : 1); >> + if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_GPIO)) >> + gpio_set_value(cs->line, >> + spi->mode & SPI_CS_HIGH ? 0 : 1); >> } > > This isn't going to work with system designs which ignore the /CS line > the controller has and just use a GPIO instead. This is very common, > for example when connecting multiple devices to the same SPI bus. As per grant's comment i would remove the quirk option and check for "cs-gpio" property to handle /CS. When multiple devices are connected to the same spi bus, "cs-gpio" entry would exist in the dts file, and works with /CS gpio lines. > > It seems like there's really two changes here. One change is making the > provision of pinmux information optional, the other is allowing the user > to use the controller /CS management rather than using GPIO. As suggested i would make two changes. 1. would parse the "gpios" property and make decision whether to use gpios/dedicated pins for miso/miso/clk. 2.would parse "cs-gpio" property from dts node to handle the chip select correct me if my understanding is wrong
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